Conventionally, execution of actions has been managed according to an ECA rule including a set of three elements, an event, a condition and an action. Also, as management of tasks similar to actions, execution of the tasks has been managed by multitasking.
In such management of the execution of the actions, there has been known a method for managing the execution based on the priority. There has also been known a method for managing the execution according to an elapsed time since the execution timing. Examples of documents disclosing such technologies include Japanese National Publication of International Patent Application No. 2012-519547, Japanese Laid-open Patent Publication Nos. 1-292539 and 2011-172180, and the like, for example.